Project description:We have identified loss of deiminated MA-Brent-1 (an RNA and export binding protein) in the retinal ganglion cells (RGCs) in multiple sclerosis and in glaucoma eyes compared to normal controls. Deimination refers to posttranslational modification of protein bound arginine (not free arginine) in citrulline. Our preliminary studies suggest binding of different repertoire of RNA by non-deiminated and deiminated MA-Brent-1. In vitro, in neurites of cultured RGCs and hippocampal neurons, the select mRNA translation is enhanced by addition of deiminated but not non-deiminated MA-Brent-1. These observations suggest that lack of deiminated MA-Brent-1 has consequences for protein synthesis, remodeling and plasticity of RGCs/neurons. Identification of RNA species bound by deiminated and non-deiminated MA-Brent-1 will enable us there further verification and determining the role that deimination plays in biological function of MA-Brent-1 in multiple sclerosis and glaucoma. To summarize identification of RNA species bound by deiminated and non deiminated MA-Brent-1 will enable us to gain further insight into role of deimination in the overall disease process. To identify the RNA species bound by deiminated and non-deiminated MA-Brent-1 The deiminanted MA-Brent-1 binds to a different repertoire of RNA and non-deiminated MA-Brent-1. Corollary to this hypothesis is that the deiminated MA-Brent-1 enhances translation for bound species of RNA. Loss of deimination results in less dendritic protein synthesis and has consequences for remodeling and plasticity in multiple sclerosis and glaucoma RGCs where lack of deimination (compared to control eyes) has been observed. About 10 microgram of purified recombinant and his-tagged non-deiminated MA-Brent-1 or deiminated MA-Brent-1 will be incubated with about 400 microgram of total RNA. The RNA bound his-tagged protein will be incubated with about 100 microliters of Ni-NTA beads and loaded onto a mini column. The column will be washed with 50 volumes of binding buffer. The bound his-tagged protein will be released using 100 mM immidazole in the binding buffer. The MA-Brent-1 bound RNA will be recovered by boiling the protein in 0.25% SDS followed by purification of RNA using columns or using a 4% PAGE-0.8% agarose composite gel followed by gel purification. The composite gel RNA purification is routine practice in the laboratory. RNA binding experiment for each protein variant (deiminated or non-deiminated) MA-Brent-1 will be repeated twice. Identified RNA species common in both binding experiments for a given species will be candidates for further pursuit. The recombinant purified MA-Brent-1 will be subjected to deimination by incubating with recombinant peptidylarginine deiminase type II (PAD2). PAD2 is a C-terminus GST tag fusion protein and will be purified using GST column. Deiminated and non-deiminated MA-Brent-1, C-terminal his-tag fusion proteins will be purified using Ni-NTA beads/column and immidazole containing buffer as eluents.
Project description:We have identified loss of deiminated MA-Brent-1 (an RNA and export binding protein) in the retinal ganglion cells (RGCs) in multiple sclerosis and in glaucoma eyes compared to normal controls. Deimination refers to posttranslational modification of protein bound arginine (not free arginine) in citrulline. Our preliminary studies suggest binding of different repertoire of RNA by non-deiminated and deiminated MA-Brent-1. In vitro, in neurites of cultured RGCs and hippocampal neurons, the select mRNA translation is enhanced by addition of deiminated but not non-deiminated MA-Brent-1. These observations suggest that lack of deiminated MA-Brent-1 has consequences for protein synthesis, remodeling and plasticity of RGCs/neurons. Identification of RNA species bound by deiminated and non-deiminated MA-Brent-1 will enable us there further verification and determining the role that deimination plays in biological function of MA-Brent-1 in multiple sclerosis and glaucoma. To summarize identification of RNA species bound by deiminated and non deiminated MA-Brent-1 will enable us to gain further insight into role of deimination in the overall disease process. To identify the RNA species bound by deiminated and non-deiminated MA-Brent-1; The deiminanted MA-Brent-1 binds to a different repertoire of RNA and non-deiminated MA-Brent-1. Corollary to this hypothesis is that the deiminated MA-Brent-1 enhances translation for bound species of RNA. Loss of deimination results in less dendritic protein synthesis and has consequences for remodeling and plasticity in multiple sclerosis and glaucoma RGCs where lack of deimination (compared to control eyes) has been observed. About 10 microgram of purified recombinant and his-tagged non-deiminated MA-Brent-1 or deiminated MA-Brent-1 will be incubated with about 400 microgram of total RNA. The RNA bound his-tagged protein will be incubated with about 100 microliters of Ni-NTA beads and loaded onto a mini column. The column will be washed with 50 volumes of binding buffer. The bound his-tagged protein will be released using 100 mM immidazole in the binding buffer. The MA-Brent-1 bound RNA will be recovered by boiling the protein in 0.25% SDS followed by purification of RNA using columns or using a 4% PAGE-0.8% agarose composite gel followed by gel purification. The composite gel RNA purification is routine practice in the laboratory. RNA binding experiment for each protein variant (deiminated or non-deiminated) MA-Brent-1 will be repeated twice. Identified RNA species common in both binding experiments for a given species will be candidates for further pursuit. The recombinant purified MA-Brent-1 will be subjected to deimination by incubating with recombinant peptidylarginine deiminase type II (PAD2). PAD2 is a C-terminus GST tag fusion protein and will be purified using GST column. Deiminated and non-deiminated MA-Brent-1, C-terminal his-tag fusion proteins will be purified using Ni-NTA beads/column and immidazole containing buffer as eluents. Experiment Overall Design: in vitro RNA binding with deiminated and non-deiminated MA-Brent-1
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.